I found the bug with the checkout from the cart page.

(template folder....default) blue_stripe/templates
In the tpl_shopping_cart_default.php file, at about line 131 look for this code:

<!--bof shopping cart buttons-->
<div class="buttonRow forward"><?php echo '<a href="' . zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL') . '">' . zen_image_submit(BUTTON_IMAGE_CHECKOUT, BUTTON_CHECKOUT_ALT) . '</a>'; ?></div>

Replace with:

<!--bof shopping cart buttons-->
<div class="buttonRow forward"><?php echo '<a href="' . zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL') . '">' . zen_image_button(BUTTON_IMAGE_CHECKOUT, BUTTON_CHECKOUT_ALT) . '</a>'; ?></div>
</div>

However weird that looks the extra </div> tag at the end fixed the problem for me.

Good Luck...